Novel diamagnetism and electronic states of Dirac fermions under magnetic field revealed by NMR spectroscopy

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K03450
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: University of Hyogo
• Principal Investigator: Nakai Yusuke 兵庫県立大学, 理学研究科, 准教授 (90596842)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 核磁気共鳴 / NMR / ディラック電子

Outline of Final Research Achievements

The study of Dirac fermion, which can be regarded as electrons with zero mass, has been making remarkable progress in various condensed matter systems. In this research, we focused on black phosphorus, a candidate material for Dirac semimetals, and performed nuclear magnetic resonance measurements under controlled pressure and magnetic fields. We observed unique magnetic field responses that cannot be explained without considering the zero-mode Landau level, which is direct evidence of Dirac fermions. From these responses, we also found that the Fermi velocity of the Dirac fermions can be estimated.

Free Research Field

固体物理

Academic Significance and Societal Importance of the Research Achievements

本研究では、圧力と磁場で容易にバンド構造とキャリア数を制御できる黒リンの特性を活かし、圧力下での黒リンのディラック半金属相に関する理解を大きく進展させた。本研究で実証した核磁気共鳴法によるバンドトポロジー同定法は、圧力・磁場下でトポロジカルなバンド構造を検証する実験的手段が現状では限られていることを考えると、黒リンに限らず、様々な物質のトポロジカルな電子状態を微視的に解明する新たな手法として意義を持つ重要な成果である。